From source to mouth, the River Gambia

Jason Florio, Helen Jones-Florio, Abdou Ndong, Ebou Jarju and Yousef Keita prepare to leave Kedougou, Senegal on the first day of their River Gambia expedition

Photographer Jason Florio and his wife Helen spent three months following the course of the River Gambia from its source in the remote Fouta Djallon highlands of Guinea, through Senegal and The Gambia.

Their total journey covered more than 650miles (1,045km), the majority by canoe and the rest by motorcycle, accompanied by two Gambian fishermen. The expedition was in part, following in the footsteps of 19th Century explorers Mungo Park and Gaspard Mollien.

Mollien was a French explorer who, in 1818, became the first European to visit the source deep in the highlands of Guinea, and his book formed the basis for their exploration. The aim of the project was to create a modern day account of the communities who live and work along the river's course.

"Our basic training before the expedition was taking our folding Canadian-style canoes up and down the bucolic Wey Navigation canal in Surrey, using waterside pubs as convenient rest stops," said Florio.

While the pubs were no doubt welcome, once in Africa the rest stops took on a different feel.

"Most nights we would wild camp on the river bank, and on one occasion on a small sandbar in the middle of the river when the banks were too steep to scale," Florio said. "At night we would we build a big fire, and keep it going all night, to ward off wildlife, especially hippos - just in case we had inadvertently pitched our tents on one of their pathways to and from the river."

While in Senegal, they encountered gold miners who would descend small narrow shafts that could extend 20m (65ft) down into the earth where they would extract chunks of gold-bearing quartz. This is then mixed with a mercury amalgam to separate the gold.

"We had been told that these camps resembled an African version of the Wild West gold rush towns, dangerous and unruly places - that we should definitely avoid. But all we found was hospitality among people working desperately hard in dangerous unregulated conditions, in the hopes of escaping a cycle of poverty."

In complete contrast to the River Gambia's humble origins, the latter section of the river, at its estuary where it flows into the Atlantic Ocean, expands to more than six miles (10km) wide.

"The wind blowing from the north created rolling waves which, in the shallows near the seeming safety of the shore, broke against our port bow - filling our two canoes with water, now lashed together with bamboo and rubber strips, to create a catamaran, in hopes of making it more stable. Our only course of action, to avoid getting waterlogged, was to push far out and over the waves, almost into the middle of the vast ocean-like river. We felt utterly vulnerable and prayed our fragile, rubberised craft would not break apart."

But they made it and returned to tell the tale. Here's a selection of the pictures they took:

Image caption A team of Senegalese men punting a raft carrying a generator for use at a banana plantation
Image caption Hawa Jallow, a member of the Santa Yalla Kaffo, a collective of women who work together to harvest rice near the River Gambia at Kaur
Image caption A female migrant worker from Mali pulls up fishing pots
Image caption Amadou Djallow, a tailor by day and hunter by night, is pictured as his home in Hore Dimma, source of the River Gambia
Image caption The River Gambia expedition team descending the Fouta Djallon Highlands from the source of River Gambia
Image caption A village elder relaxes outside an abandoned colonial warehouse in Kuntuar village, once a commercial hub of the peanut trade
Image caption A Senegalese family from the Toucouleur tribe at their seasonal fishing camp at Carrolls Wharf in The Gambia
Image caption A small ferry called a barra lands on the south bank of River Gambia in eastern Gambia surrounded by cattle owned by Fula tribesmen
Image caption Bakary Dabo the Alkalo (chief) of Diagabu Tenda, on the edge of River Gambia
Image caption A gold miner relaxes after a shift at an artisanal mine in Senegal on the banks of the River Gambia
Image caption Senegalese Children from the Toucouleur tribe
Image caption Migrant workers from Guinea-Bissau collecting oysters along the shores of a tributary of the River Gambia
Image caption Musa Jallow with his pet patas monkey which he rescued after hunters killed its mother
Image caption A watchman relaxes on a jetty near the small Gambian village of Bonto